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Wyszukujesz frazę "hybrid model" wg kryterium: Temat


Tytuł:
Demand forecasting: an alternative approach based on technical indicator Pbands
Autorzy:
Kolková, Andrea
Ključnikov, Aleksandr
Powiązania:
https://bibliotekanauki.pl/articles/19233720.pdf
Data publikacji:
2021
Wydawca:
Instytut Badań Gospodarczych
Tematy:
demand forecasting
neural network
BATS
hybrid model
Pbands
Opis:
Research background: Demand forecasting helps companies to anticipate purchases and plan the delivery or production. In order to face this complex problem, many statistical methods, artificial intelligence-based methods, and hybrid methods are currently being developed. However, all these methods have similar problematic issues, including the complexity, long computing time, and the need for high computing performance of the IT infrastructure. Purpose of the article: This study aims to verify and evaluate the possibility of using Google Trends data for poetry book demand forecasting and compare the results of the application of the statistical methods, neural networks, and a hybrid model versus the alternative possibility of using technical analysis methods to achieve immediate and accessible forecasting. Specifically, it aims to verify the possibility of immediate demand forecasting based on an alternative approach using Pbands technical indicator for poetry books in the European Quartet countries. Methods: The study performs the demand forecasting based on the technical analysis of the Google Trends data search in case of the keyword poetry in the European Quartet countries by several statistical methods, including the commonly used ETS statistical methods, ARIMA method, ARFIMA method, BATS method based on the combination of the Cox-Box transformation model and ARMA, artificial neural networks, the Theta model, a hybrid model, and an alternative approach of forecasting using Pbands indicator.  The study uses MAPE and RMSE approaches to measure the accuracy. Findings & value added: Although most currently available demand prediction models are either slow or complex, the entrepreneurial practice requires fast, simple, and accurate ones. The study results show that the alternative Pbands approach is easily applicable and can predict short-term demand changes. Due to its simplicity, the Pbands method is suitable and convenient to monitor short-term data describing the demand. Demand prediction methods based on technical indicators represent a new approach for demand forecasting. The application of these technical indicators could be a further forecasting models research direction. The future of theoretical research in forecasting should be devoted mainly to simplifying and speeding up. Creating an automated model based on primary data parameters and easily interpretable results is a challenge for further research.
Źródło:
Oeconomia Copernicana; 2021, 12, 4; 1063-1094
2083-1277
Pojawia się w:
Oeconomia Copernicana
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model hybrydowy łuku do badania oddziaływania odbiornika plazmowego gliding arc na sieć zasilającą
Hybrid arc model for testing the interaction of the gliding arc plasma receiver on the power supply network
Autorzy:
Sawicki, Antoni
Gryś, Sławomir
Powiązania:
https://bibliotekanauki.pl/articles/267707.pdf
Data publikacji:
2019
Wydawca:
Politechnika Gdańska. Wydział Elektrotechniki i Automatyki
Tematy:
łuk elektryczny
model Woronina
model hybrydowy
electric arc
Voronin model
hybrid model
Opis:
Na podstawie analizy warunków pracy plazmotronu gliding arc zaproponowano zastosowanie zmodyfikowanego modelu Woronina łuku elektrycznego do symulacji procesów w układzie zasilania łuku. Postać hybrydowa modelu umożliwia jego wykorzystanie w szerokim zakresie prądu roboczego. Ponadto model ten uwzględnia dynamikę zmian długości kolumny plazmowej. Przeprowadzone symulacje wykazały efektywność stosowania opracowanego makromodelu oraz umożliwiły zbadanie wpływu plazmotronu na sieć zasilającą w warunkach braku i stosowania różnego rzędu filtrów biernych.
Based on the analysis of the operating conditions of the gliding arc plasmotron, a modified Voronin model of the electric arc was proposed to simulate processes in the arc power supply system. The hybrid form of the model allows its use in a wide range of supply current. In addition, this model takes into account the dynamics of length changes of the arc column. The simulations showed the effectiveness of using the developed macromodel and allowed the study of the impact of the plasmotron on the power supply network under the conditions of using different passive LC filters inserted before transformer. The main conclusions are as follows: higher filter rank increases the device's on-off current and at the same time reduces the start voltage on the filter; the higher the filter rank, the greater the attenuation of voltage changes - the waveform has a milder shape by reducing fighter frequencies. The possible future work can be quantitative analysis of energy quality for results of simulations and real measurements with experimental stand including filter, transformer and gliding plasmotron.
Źródło:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej; 2019, 67; 123-127
1425-5766
2353-1290
Pojawia się w:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic investigations of electromechanical coupling effects in the mechanism driven by the stepping motor
Badanie efektów dynamicznych sprzężeń elektromechanicznych w mechaniźmie napędzanym silnikiem skokowym
Autorzy:
Szolc, T.
Pochanke, A.
Powiązania:
https://bibliotekanauki.pl/articles/280500.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
electro-mechanical vibrations
drive system
stepping motor
hybrid model
Opis:
In the paper, an analysis of transient and steady-state electro-mechanical vibrations of a precise drive system driven by a stepping motor is performed. These theoretical investigations are based on a hybrid structural model of the mechanical system as well as on the classical circuit model of the stepping motor. The main purpose of these studies is to indicate essential differences between the torsional dynamic responses obtained for the considered object regarded respectively as electro-mechanically coupled and uncoupled. From the computational results, it follows that these differences are qualitatively and quantitatively essential from the viewpoint of possibly precise and reliable operation of the drive systems. Here, torsional vibrations of the drive system significantly influence the electro-mechanical coupling effects, which emphasizes their importance in dynamic analyses.
W pracy przeprowadzono analizę przejściowych i ustalonych drgań elektromechanicznych precyzyjnego układu mechanicznego napędzanego silnikiem skokowym. Badania teoretyczne wykonano za pomocą hybrydowego modelu strukturalnego układu napędowego oraz klasycznego obwodowego modelu silnika skokowego. Głównym celem dokonanego studium było wykazanie istotnych różnic pomiędzy odpowiedziami dynamicznymi drgającego skrętnie obiektu traktowanymi jako elektromechanicznie sprzężone i rozprzężone. Na podstawie uzyskanych wyników można stwierdzić, że te różnice są jakościowo i ilościowo znaczące z punktu widzenia precyzyjnego i niezawodnego działania układu napędowego.Wykazano, iż drgania skrętne układu napędowego istotnie wpływają na efekt sprzężenia elektromechanicznego, co uzasadnia ważność jego uwzględniania przy przeprowadzaniu tego typu analiz.
Źródło:
Journal of Theoretical and Applied Mechanics; 2012, 50, 2; 653-673
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling and forecasting monthly Brent crude oil prices: a long memory and volatility approach
Autorzy:
AlـGounmeein, Remal Shaher
Ismail, Mohd Tahir
Powiązania:
https://bibliotekanauki.pl/articles/1047374.pdf
Data publikacji:
2021-03-03
Wydawca:
Główny Urząd Statystyczny
Tematy:
ARFIMA
volatility
fGARCH
sGARCH
modelling and forecasting
hybrid model
Opis:
The Standard Generalised Autoregressive Conditionally Heteroskedastic (sGARCH) model and the Functional Generalised Autoregressive Conditionally Heteroskedastic (fGARCH) model were applied to study the volatility of the Autoregressive Fractionally Integrated Moving Average (ARFIMA) model, which is the primary objective of this study. The other goal of this paper is to expand on the researchers' previous work by examining long memory and volatilities simultaneously, by using the ARFIMA-sGARCH hybrid model and comparing it against the ARFIMA-fGARCH hybrid model. Consequently, the hybrid models were configured with the monthly Brent crude oil price series for the period from January 1979 to July 2019. These datasets were considered as the global economy is currently facing significant challenges resulting from noticeable volatilities, especially in terms of the Brent crude prices, due to the outbreak of COVID-19. To achieve these goals, an R/S analysis was performed and the aggregated variance and the Higuchi methods were applied to test for the presence of long memory in the dataset. Furthermore, four breaks have been detected: in 1986, 1999, 2005, and 2013 using the Bayes information criterion. In the further section of the paper, the Hurst Exponent and Geweke-Porter-Hudak (GPH) methods were used to estimate the values of fractional differences. Thus, some ARFIMA models were identified using AIC (Akaike Information Criterion), BIC (Schwartz Bayesian Information Criterion), AICc (corrected AIC), and the RMSE (Root Mean Squared Error). In result, the following conclusions were reached: the ARFIMA(2,0.3589648,2)-sGARCH(1,1) model and the ARFIMA(2,0.3589648,2)-fGARCH(1,1) model under normal distribution proved to be the best models, demonstrating the smallest values for these criteria. The calculations conducted herein show that the two models are of the same accuracy level in terms of the RMSE value, which equals 0.08808882, and it is this result that distinguishes our study. In conclusion, these models can be used to predict oil prices more accurately than others.
Źródło:
Statistics in Transition new series; 2021, 22, 1; 29-54
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A hybrid model of flooding of the ro-ro ships in damaged conditions
Autorzy:
Gerigk, M. K.
Jachowski, J.
Sargun, J.
Powiązania:
https://bibliotekanauki.pl/articles/117095.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
hybrid model
hybrid model of flooding
ro-ro ships
damaged condition
ship in damaged condition
hydrodynamics
Gdansk University of Technology
flooding process
Opis:
The paper presents some results on investigations concerning development of a hybrid model for assessment of performance of the ro-ro ships in damaged conditions. The model is devoted towards assessing the performance of the damaged ro-ro ships at the preliminary stage of design. The key problems associated with preparing of such the model are associated with working out a method of assessment of the damaged ro-ro ships performance, investigating all the phenomena which associated with the flooding process of the damaged ro-ro ships and preparing the model itself. Introducing the method of assessment of the damaged ro-ro ships performance it has been assumed that there is a dependence between the arrangement of internal spaces of a ro-ro ship and flooding process. The major phenomena which have been decided to take into account when considering flooding of the ro-ro ships are the flooding understood as the flow of external water into the data damaged compartment, impact of the flooding water on the ship structure and damaged ro-ro ship motion. Knowing the damaged ro-ro ship motion characteristics in time domain it is relatively easy to assess the damaged ro-ro ship performance according to the heeling angle and assess the ro-ro ship design according to the data arrangement of internal spaces. The last research issue is to investigate if the proposed model may be appropriate tool for assessing the performance of the ro-ro ships in damaged conditions at the preliminary stage of design. The aim of this paper is to show how to incorporate the dynamics of the damaged ro-ro ships when assessing the ship performance and safety at the preliminary stage of design. The basic information on the model for estimation of the damaged ro-ro ship behavior during the flooding process is presented. The complexity of this model is shown depending on the approach applied to consider the flooding process itself. The model is devoted towards assessment of performance of the damaged ro-ro ships and it is still under the development according to a Ph.D. research at the Faculty of Mechanical Engineering Gdańsk University of Technology.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2019, 13, 2; 347-354
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An improved formula for dead time correction of G-M detectors
Autorzy:
Arkani, M.
Khalafi, H.
Powiązania:
https://bibliotekanauki.pl/articles/147009.pdf
Data publikacji:
2013
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
dead time model
Geiger-Müller (G-M) detector
decaying source experiment
hybrid model
Opis:
Different analytical formulae have been described in the literature to modify response of Geiger-Müller (G-M) detectors. In this work, improvement of a previously proposed dead time correction formula was investigated. A set of experimental data of a decaying source was the basis of the analysis. A general agreement is seen with the experimental data. The result was compared with those obtained by the original work. Numerical aspects were also examined.
Źródło:
Nukleonika; 2013, 58, 4; 533-536
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electric arc models with non-zero residual conductance and with increased energy dissipation
Autorzy:
Sawicki, Antoni
Powiązania:
https://bibliotekanauki.pl/articles/1955184.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Cassie model
electric arc
hybrid model
Mayr model
model Cassiego
łuk elektryczny
model hybrydowy
model Mayr
Opis:
This paper describes modifications of the Mayr and Cassie models of the electric arc. They include the phenomena of increased heat dissipation and non-zero residual conductance when the current passes through zero. The modified models are combined into a new hybrid model connecting them in parallel and activated by a weight function. Two cases of functional dependence of models on current intensity and instantaneous conductance are considered. Mathematical models in differential and integral forms are presented. On their basis, computer macromodels are created and simulations of processes in circuits with arc models are performed. The families of static and dynamic arc voltage and current characteristics are presented.
Źródło:
Archives of Electrical Engineering; 2021, 70, 4; 819-834
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bringing Kano’s perspective to AHP: the 2D-AHP decision model
Autorzy:
Jung, U.
Yim, S.
Lim, S.
Kim, C.
Powiązania:
https://bibliotekanauki.pl/articles/407247.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
analytic hierarchy process (AHP)
Kano model
hybrid model
multicriteria decision making
two dimension perspective
Opis:
AHP and the Kano model are such prevalent TQM tools that it may be surprising that a true hybrid decision-making model has so far eluded researchers. The quest for a hybrid approach is complicated by the differing output perspective of each model, namely discrete ranking (AHP) versus a multi-dimensional picture (Kano). This paper presents a hybrid model of AHP and Kano model, so called two-dimension AHP (2D-AHP). This paper first compares the two approaches and justifies a hybrid model based on a simple conceit drawn from the Kano perspective: given a decision hierarchy, child and parent elements can exhibit multi-dimension relationships under different circumstances. Based on this premise, the authors construct a hybrid two-dimension AHP model whereby a functionaldysfunctional question-pair technique is incorporated into a traditional AHP framework. Using the proposed hybrid model, this paper provides a practical test case of its implementation. The 2D-AHP approach revealed important evaluation variances obscured through AHP, while a survey study confirmed that the 2D-AHP approach is both feasible and preferred in some respects by respondents. Although there have been rich research efforts to combine AHP and Kano model, most of them is simply about a series of individual usage of each methodology. On the other hand, the type of hybridization between AHP and Kano model in this paper is quite unique in terms of the two dimensional perspective. The model provides a general approach with application possibilities far beyond the scope of the test case and its problem structure, and so calls for application and validation in new cases.
Źródło:
Management and Production Engineering Review; 2016, 7, 4; 16-26
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hybrydowy model biznesowy linii lotniczych jako determinanta rozwoju przewoźników lotniczych
Hybrid model of airlines as a determinant of the development of air carriers
Autorzy:
Szymczak, Anna
Powiązania:
https://bibliotekanauki.pl/articles/697890.pdf
Data publikacji:
2018
Wydawca:
Szkoła Główna Handlowa w Warszawie
Tematy:
hybrid model
air services market
air carrier
model hybrydowy
rynek usług lotniczych
przewoźnik lotniczy
Opis:
The aviation market is one of the most dynamic factors determining economic develop-ment in the world. In addition, it is susceptible to economic and political crises. The air services market is also characterized by a very large diversity of clients within the market segments. Adaptation of an appropriate business model may be a condition for success, with the increase of ASK, RPK and LF ratios. The aim of the work is to indicate the basic elements of business models of airlines that make up the hybrid model. The article also describes the evolution of Ryanair, which from the carrier emphasizing the lowest price aspires to the carrier offering flights with better quality than its competitors. The source materials of the study are available literature on the subject, own analysis based on secondary sources.
Dynamicznie rozwijający się rynek usług lotniczych jest ważną determinantą rozwoju gospodarczego, choć jest podatny na kryzysy ekonomiczne i polityczne. Segment usług lotniczych charakteryzuje się również bardzo dużym zróżnicowaniem klientów w ramach segmentów rynku. Dostosowanie odpowiedniego modelu biznesowego może warunkować osiągnięcie sukcesu, tj. przy podwyższeniu wskaźników ASK, RPK oraz LF. Celem artykułu jest wskazanie podstawowych elementów modeli biznesowych linii lotniczych, ze szczególnym uwzględnieniem modelu hybrydowego. Jako przykład posłużyły linie lotnicze Ryanair, które z przewoźnika kładącego nacisk na najniższą cenę pretendują do przewoźnika oferującego przeloty z lepszą jakością niż konkurencja. Materiałami źródłowymi opracowania jest dostępna literatura przedmiotu oraz własne analizy oparte na źródłach wtórnych.
Źródło:
Kwartalnik Nauk o Przedsiębiorstwie; 2018, 48, 3; 53-60
1896-656X
Pojawia się w:
Kwartalnik Nauk o Przedsiębiorstwie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The number of clusters in hybrid predictive models: does it really matter?
Autorzy:
Łapczyński, Mariusz
Jefmański, Bartłomiej
Powiązania:
https://bibliotekanauki.pl/articles/1046637.pdf
Data publikacji:
2020
Wydawca:
Główny Urząd Statystyczny
Tematy:
hybrid predictive model
k-means algorithm
decision trees
Opis:
For quite a long time, research studies have attempted to combine various analytical tools to build predictive models. It is possible to combine tools of the same type (ensemble models, committees) or tools of different types (hybrid models). Hybrid models are used in such areas as customer relationship management (CRM), web usage mining, medical sciences, petroleum geology and anomaly detection in computer networks. Our hybrid model was created as a sequential combination of a cluster analysis and decision trees. In the first step of the procedure, objects were grouped into clusters using the k-means algorithm. The second step involved building a decision tree model with a new independent variable that indicated which cluster the objects belonged to. The analysis was based on 14 data sets collected from publicly accessible repositories. The performance of the models was assessed with the use of measures derived from the confusion matrix, including the accuracy, precision, recall, F-measure, and the lift in the first and second decile. We tried to find a relationship between the number of clusters and the quality of hybrid predictive models. According to our knowledge, similar studies have not been conducted yet. Our research demonstrates that in some cases building hybrid models can improve the performance of predictive models. It turned out that the models with the highest performance measures require building a relatively large number of clusters (from 9 to 15).
Źródło:
Przegląd Statystyczny; 2019, 66, 3; 228-238
0033-2372
Pojawia się w:
Przegląd Statystyczny
Dostawca treści:
Biblioteka Nauki
Artykuł

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